spark plug gap

04sxt2.0 · Post by **04sxt2.0** » Wed Jul 25, 2007 5:46 pm

what is the sprak plug gap for our cars?

dgodard · Post by **dgodard** » Wed Jul 25, 2007 5:54 pm

JRM · Post by **JRM** » Thu Jul 26, 2007 12:45 am

dgodard wrote:.035

kc2005ptgt · Post by **kc2005ptgt** » Thu Jul 26, 2007 2:03 am

JRM wrote:
dgodard wrote:.035

OB · Post by OB » Thu Jul 26, 2007 2:06 am

kc2002acr wrote:
JRM wrote:
dgodard wrote:.035

JRM · Post by **JRM** » Thu Jul 26, 2007 2:06 am

OB wrote:
kc2002acr wrote:
JRM wrote:

05NeonSE · Post by **05NeonSE** » Thu Jul 26, 2007 2:17 am

i hate to stick out like a sore thumb but

mike9fore wrote:I just looked over my Haynes Guide and it states the following:

Gap for 2000-2003 Models:

0.033 to 0.038

Gap for 2004-2005 Models:

0.044

JRM · Post by **JRM** » Thu Jul 26, 2007 2:21 am

JRM wrote:
OB wrote:
kc2002acr wrote:

contagious18 · Post by **contagious18** » Thu Jul 26, 2007 2:29 am

JRM wrote:
JRM wrote:
OB wrote:

.035

danielc24 · Post by **danielc24** » Thu Jul 26, 2007 2:52 am

contagious18 wrote:
JRM wrote:
JRM wrote:
.035

.035

BlackRoseRacing · Post by **BlackRoseRacing** » Thu Jul 26, 2007 5:06 am

Stock ignition - .040(my recomendation)
Aftermarket ignition - .050+ depending on ignition setup

Note:
These gaps are receomended for N/A applications, Forced induction gapping is different....

04sxt2.0 · Post by **04sxt2.0** » Thu Jul 26, 2007 7:12 am

i just replaced the plugs and wires, but the plugs are at a .32 gap.. i didn't think they were gapped to the right spec..

kc2005ptgt · Post by **kc2005ptgt** » Thu Jul 26, 2007 11:28 am

BlackRoseRacing wrote:Stock ignition - .040(my recomendation)
Aftermarket ignition - .050+ depending on ignition setup

Note:
These gaps are receomended for N/A applications, Forced induction gapping is different....

For real, .050+??? What will that do?

half_twisted · Post by **half_twisted** » Thu Jul 26, 2007 12:15 pm

kc2002acr wrote:
BlackRoseRacing wrote:Stock ignition - .040(my recomendation)
Aftermarket ignition - .050+ depending on ignition setup

Note:
These gaps are receomended for N/A applications, Forced induction gapping is different....
For real, .050+??? What will that do?

i thought r/t had .042 gap

Post by **racer12306** » Thu Jul 26, 2007 12:15 pm

it will give you a bigger flame front, thus better burning.

but in stock for the factory says .035", i think that haynes manual was wrong, which wouldn't be the first time.

kc2005ptgt · Post by **kc2005ptgt** » Thu Jul 26, 2007 12:21 pm

racer12306 wrote:it will give you a bigger flame front, thus better burning.

but in stock for the factory says .035", i think that haynes manual was wrong, which wouldn't be the first time.

As for stock r/t gap, no, under my hood it says in plain english and even some greek and latin, .035 spark plug gap -- do I need to take a picture for proof?

As for running it higher, maybe I will gap it a little bigger since I am running a bigger cam and most of the bolt ons.

dgodard · Post by **dgodard** » Thu Jul 26, 2007 12:49 pm

Factory says underhood....all 2.0 SOHC .035

OB · Post by OB » Thu Jul 26, 2007 4:15 pm

According to my FSM it is .035

Unless you have a highly developed ignition system and a matching fuel system and engine, anything else isnt a wise idea.

04sxt2.0 · Post by **04sxt2.0** » Thu Jul 26, 2007 8:20 pm

stupid guy at advanced auto parts handed me some that were gapped to small i just gap them to .35-.38. car is running much better but i still think it has a skip

fixitmattman · Post by **fixitmattman** » Thu Jul 26, 2007 9:43 pm

I like mine at .030

04sxt2.0 · Post by **04sxt2.0** » Thu Jul 26, 2007 9:53 pm

they were at lik .20, when i pulled them out today, i figured i check that before i spend 65 on a coil.

BlackRoseRacing · Post by **BlackRoseRacing** » Fri Jul 27, 2007 6:30 am

My R/T was missing a little bit on the top end (around 6200rpm) with the gap set at .035 so I opened it up to .040 and it smoothed it out. Im actually running a bigger gap now since Ive got the crane ignition setup.....
My quick 2 cents....

04sxt2.0 · Post by **04sxt2.0** » Fri Jul 27, 2007 6:58 am

mine is missing at idle it has a real rough idle around 1200-1400 rpm. then it smooths out.. i am going to check and see if it does it this morning.. hopefully it doesn't

OB · Post by OB » Fri Jul 27, 2007 1:47 pm

I thought about tuning via plug gap adjustment, but the difference is so minimal that I havent gotten around to it. .005 is very small, but I suppose if you guys are noticing a difference then ill give it a shot. Mine pulls strong to redline (well just as strong as a non mag can

) but I could understand why a bigger flame front might help WOT combustion while in open loop. Whats the deal with your ign system chris?

60trim · Post by **60trim** » Fri Jul 27, 2007 5:07 pm

I gap mine at .038 and I'm on 7psi with my turbo set up. I'm running 1 step colder NGKs.

bone-yard-racing · Post by **bone-yard-racing** » Fri Jul 27, 2007 5:28 pm

I use on a standard SOHC with bolt on's: STOCK CHAMPIONS 0.033-0.037 dosent make much difference, and I index the

NGC Magnum: STOCK CHAMPIONS Right at 0.035 or it gets really un-happy also indexed

BlackRoseRacing · Post by **BlackRoseRacing** » Sun Jul 29, 2007 9:03 am

Yes and no. A spark plug part number might fit hundreds of engines, and although the factory will typically set gap to a pre-selected setting, this gap may not be the right one for your particular engine, and may not take into account modifications that you may have performed to the engine.

Insufficient spark plug gap can cause pre-ignition, detonation, even engine damage. Too much gap can result in a higher rate of misfires, noticeable loss of power, plug fouling, and poor economy.

When you raise compression or add forced induction (a turbo system, nitrous, or supercharger kit), you must lower the gap (reduce gap about .004" for every 50 hp you add on an V-8 engine, for a Harley-Davidson V-2 engine every 12.5 hp you add). However, when you add a high power ignition system (such as those offered by MSD, Crane, Nology,) you can open the gap back up about .002"-.005".

As an example, let's use a hypothetical `96 350 Chevrolet LT1 engine build-up. The standard gap is .050" for an un-modified LT1. We'll add 150hp Nitrous, so we must lower the gap about .012" to .038". We then decide to add that killer MSD 6A/Crane Hi-6 box and, using our guidelines as outlined above, we can now open the gap up .002"-.005" to about .040"- .043". By following this basic guideline should get you very close.

Further experimentation may be necessary, but by always starting with a larger gap than it thought necessary to reduce the risk of detonation, you should be safe.

Here is a link to plug listing's and other information:
http://www.sparkplugs.com/default.asp

Proper Plug Gapping:

Proper gapping of the spark plug is necessary to get maximum spark energy, lowest RFI release as well as what is best for the longevity of the secondary ignition components (coil, cap, rotor, wires, plugs).
When checking plug gaps, the correct way is to use ONLY wire gauges, though many of us are using the slider style gapping tools. These flat or feeler gauge style gauges do not accurately measure true width of spark plug gap.
When increasing the gap size for our high performance applications utilizing advanced ignition systems such as Mallory, Accel, Jacobs, Crane and Holley ... it is important never to go more than plus or minus .008". This is to maintain parallel surfaces between ground and the center electrodes.
Something many do not know, is that with Higher Compression ratios and Superchargers as well as Nitrous, in many cases smaller spark plug gaps must be used as well as the use of a much hotter ignition system (see above). These higher cylinder pressures require more energy to jump the spark plug gap.
The rule of thumb on plug gaps is to open them up in .002" increments at a time. When the car (race vehicle) begins to lose power or slow down then go back .001-.002" and this in most cases is the optimum gap.

Hope this information helps....